Premier League elite forced to deal with rivals due to wages, lack of options
From an Arsenal perspective, if there is one good thing to come from Bayern Munich's strong interest in Alexis Sanchez, it is that it offers the club a chance to sell their star man to a side not competing in the Premier League.
Manchester City also want Sanchez and appear willing to outbid Bayern to sign him; Chelsea, too, would be prepared to break their own transfer record by paying more than the £50m they invested in Liverpool's Fernando Torres in 2011.
With just one year left to run on his contract at the Emirates, Sanchez has shown little desire to negotiate a new deal, so Arsenal are faced with the dilemma of keeping the Chilean against his will and lose him for nothing next year or cash in now and sell to the highest bidder.
Both options are pretty unpalatable for a club of Arsenal's stature. The days of allowing the likes of Samir Nasri and Robin van Persie leave for Manchester City and Manchester United respectively were supposed to be over, but Sanchez has left them facing the same problem again.
Bayern are the face-saving option. Not only will the German champions pay Sanchez as much, if not more, than City or Chelsea, they will also enable Arsenal to sell without strengthening a domestic rival at the same time.
Without Champions League football, Arsenal won't have to face Bayern, so it would be a case of "out of sight, out of mind" with a hefty cheque thrown in to soften the blow of losing him.
However, Arsenal should count themselves lucky to have Bayern knocking at the door. For many of their top seven rivals, there will be no alternative than to sell to each other this summer. The Premier League transfer market no longer allows them to ignore one another.
Such are the wages now being paid to squad players at Chelsea, United, City and Arsenal and, to a lesser extent, Tottenham, Liverpool and Everton, that offloading them -- or "disposals," as they are described on the balance sheet -- has become almost impossible.
Back in February 2016, United's executive vice-chairman Ed Woodward admitted publicly that the club regarded the Chinese Super League as a "useful market" for player disposals due to the fees and wages being paid by the clubs in China.
But other than Chelsea, who have successfully, and lucratively, offloaded Oscar, Ramires and John Obi Mikel to China, the Premier League's biggest clubs have been unable to use the Chinese market as a dumping ground for their highly-paid, out of favour stars.
United would love to do business with a Chinese club for Wayne Rooney, whose £300,000-a-week wages will amount to £15.6m on the Old Trafford payroll between now and the end of his contract in June 2018.
No English club would be prepared to pay even half of Rooney's United salary, while Everton, the club most likely to offer him a move within the Premier League, do not currently pay any of their players more than £100,000-a-week. Making that deal work appears an almighty challenge.
Rooney may be an exception due to his current salary, with even the biggest English clubs unable to pay him what he earns at United, but when you drop down the pecking order, many of those players who could leave the top seven clubs are too costly for the rest.
When Joe Hart completed a loan move to Torino last August, it was only signed off once City agreed that the Italian club would pay just £1m of the England goalkeeper's £6m-a-year salary.
The top clubs will subsidise loan deals for a year but beyond that they want to cash in. Yet who could pay Hart anything close to his City wages outside the top seven? West Ham, perhaps, but unless Hart takes a huge drop in earnings, or City pay up his contract, he faces being marooned at the Etihad as there won't be any takers who can offer him the same kind of deal.
If Chelsea, Liverpool or Arsenal were in the market for a new keeper, Hart's situation would be so much easier for City to resolve. And it is a different story with the likes of Alex Oxlade-Chamberlain, Chris Smalling and Kyle Walker.
Arsenal want to keep Oxlade-Chamberlain, whose contract expires next year, but Liverpool are prepared to pay the fee and wages required to take him to Anfield. Unlike Sanchez, Arsenal do not have a wealthy European club to make life easier, so they will have no option but to sell to a direct rival if Oxlade-Chamberlain puts in a transfer request.
United could offload Smalling to Arsenal and Spurs are ready to sell Walker to City because there are no other ways to get market value fees for players whose wages price out those clubs not regarded as rivals.
Some clubs will still resist any kind of trading between each other, however.
Arsenal and Tottenham will not do direct business. Nor will United and City. And no player has moved directly between United and Liverpool since Phil Chisnall did so in 1964.
But as the biggest clubs grow richer and more powerful, there may come a point where even long-standing rivals have to sell to one another simply to keep the transfer wheels turning. Otherwise, there will be a growing number of players being paid huge contracts without kicking a ball because nobody else can afford them.
Mark Ogden is a senior football writer for ESPN FC. Follow him @MarkOgden_